elessar i have under stood what u have said........but listen to my doubt and clarify it to me please......

 --------  if friction is sufficent to prevent slipping ,then tell me weather the cyl. will start pure rolling as

soon as angular vel bcomes zero or wil it slide for some time and then starts pure rolling.?

---------what will be the value of friction as soon as angular vel., bcomes zero.  tell  me weather it will adjust

itself  so as to bring pure rolling to the cyl.,. ( assume friction is suff., to prevent slipping)

 

since the cyl., is rotating in the anti- clockwise sense, friction is upward.

this will reduce the agular vel., of the cylinder.

but the cyl., will continue moving linearly downward since the downward force along the plane is greater

than the friction which is upward.

due to the angular retardation, at some point of time , the angular velocity which is in the anticlockwise sense

will bcom zero.

after this i dont know what will be the motion..................

i think 

as soon as the  angular vel., bcomes zero ,if friction is sufficient to prevent slipping , the cyl. will start rolling.

but if friction is not sufficient to prevent slipping ,  cyl., will slide.

but i am not confident about the above two lines...........................

i want anyone to anwer to my doubt ,,,,,,,,,,,,,,,,,,,,,,,,,,,,.............................waiting for the reply...............

any one please answer to my previous post.......................................................

any one please answer to my previous post.......................................................

if possible please give,me the approtpriate eqations................

if possible please give me the equations........................please..................

if possible please give me the equations........................please..................

in my earlier post coeff., of friction was = tan@.

but now i am asking if it is coeff., < tan@.

see weather i am right or not...............

firstly friction will act upward which will be trying to reduce the angular velocity but  at the same time the cylinder

will be in down ward  linear motion.

but when angular velocity becomes zero (  linear velocity not equal to zero ) what is the motion of the cylinder

from here ........................

this is where i am not able to understand.........

will it start rolling as soon as w becomes zero (  if friction is sufficient to prevent slipping)

or will it slide for sometime and then start pure rolling or what.....................

waitng for the reply.................................

a cylinder is  given an initial angular velocity w and is placed on an incline with angle of incl., @ . given that

coefficent of friction < tan@  ,  then describe the motion of the cylinder  on the plane .

waiting for the concept regarding above question..............................

any one please...............i am waiting for the reply............

 a uniform disc is given an initial linear velocity = v , and an initial angular veloctiy (in an anti clockwise sense as shown in figure) = w . Given that  2v = rw . (friction is acting on the disc)...........

in this case both linear and angular velocities become zero  at a time (i.e, in same time)

then what is its motion after both the linear velocity as well as angular velocity becomes zero.

i.e, will it stop its motion, or roll in forward direction or in backward direction ?

i think that it will stop its motion.........but i am not confident about it........so waiting for the reply...........

hello any one please answer to my above post................

im waiting for the reply.................